The present invention relates to a device for accurately forwarding articles so that their position is accurately determined, which is reversible so as to retrieve articles in a reverse direction, also in an accurate manner and which in fact is particularly suitable for handling rectangular articles.
There is an already per se well known type of rotary multi shelf article storage warehouse, of the sort shown in plan view at the right hand side of FIG. 1 of the accompanying drawings and generally designated as "A", in which as mounted to a frame 1 there are provided a plurality of horizontally running track systems spaced apart in the vertical direction, only the topmost one of which can be seen in the figure. Each of these track systems comprises an outer rail 2 and a pair of inner rails 3 on the same level, each of the outer rails 2 being shaped as an oval, and each of the inner rails 3 being straight and being located within its outer rail 2 opposing a straight stretch thereof with corresponding points on said straight stretch of the outer rail 2 and the inner rail 3 being equidistant. The spacing between each contiguous pair of the track systems in the vertical direction is substantially equal. On each of the track systems there run a plurality of wheeled shelves 4, contiguous ones of which are linked one to the next by link plates 6 fixed to their lower bottoms so as to form a train, each of said trains being driven along its track system by a train drive means which is not shown in the figure. These wheeled shelves 4 are adapted to carry rectangular (in plan view) containers 5 which are adapted for carrying small objects or the like, not shown.
Such a rotary multi shelf type article storage warehouse A is convenient for storing a multiplicity of small objects in an organized manner, as for example in a manufacturing plant for electrical or mechanical machinery, but the problem has arisen that, since generally the available space for such a warehouse A is quite limited, therefore in order desirably to exploit this available space as effectively as possible, it is desirable to leave very little distance between the containers 5 and the wheeled shelves 4 on which they rest, i.e. to make the containers 5 as large as possible and to pack them as compactly as possible in the horizontal direction. Further, for the same reasons, it is desirable to leave as little vertical free space as possible between the top of each container 5 and the lower side of the track system next above said container 5, in other words to pack the containers as compactly as possible in the vertical direction. The problem then arises that very accurate positioning of a container 5 is then required in order to place it on its appropriate wheeled shelf 4 without difficulties arising from interference with the side of said wheeled shelf 4 or from other wheeled shelves 4, and accurate handling is similarly required in order to remove a container 5 from its wheeled shelf 4 without interference. Especially, such problems arise with respect to the higher stages of the article warehouse A, and it is difficult to place containers 5 on the upper wheeled shelves 4, and to retrieve said containers 5, easily.